Siemens SINUMERIK codes
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Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 30-60 minutes

Alarm 14012

Siemens 840D 14012 - Channel block maximum subroutine level exceeded

The maximum nesting depth of 8 program levels has been exceeded. Subroutines can be called from the main program, and these in turn may have a nesting depth of 7. In interrupt routines the maximum number of levels is 4!

Siemens SINUMERIKServo/AxisIntermediate30-60 minutes

14012

Siemens 840D 14012 - Channel block maximum subroutine level exceeded

Channel block maximum subroutine level exceeded

The maximum nesting depth of 8 program levels has been exceeded. Subroutines can be called from the main program, and these in turn may have a nesting depth of 7. In interrupt routines the maximum number of levels is 4!

Safety

  • Refer to Siemens documentation
  • Ensure qualified technician performs repairs

Common Causes

  • Program contains subroutine calls nested deeper than 8 levels in main program execution
  • Interrupt routine attempting to call subroutines with nesting depth exceeding 4 levels
  • Recursive subroutine calls without proper termination creating excessive call stack
  • Multiple nested CALL statements in subprograms without returning to previous level
  • Interrupt service routine invoking subprograms that themselves call additional subroutines

Troubleshooting Steps

  1. 1Review the program structure in channel %1 block %2 to identify all CALL statements and their nesting hierarchy
  2. 2Trace the subroutine call chain and count nesting levels; main program allows 8 levels, interrupt routines limited to 4 levels
  3. 3Refactor deeply nested subroutines by consolidating functionality into fewer levels or using inline code where appropriate
  4. 4Check interrupt routines separately and verify they do not exceed 4-level nesting limit; move complex logic to called main program subroutines if needed
  5. 5Verify all subroutine calls properly return control using M17 or equivalent return statement to ensure call stack is managed correctly

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